261617215 has 8 divisors (see below), whose sum is σ = 324067968. Its totient is φ = 202542240.

The previous prime is 261617183. The next prime is 261617263. The reversal of 261617215 is 512716162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261617215 - 2⁵ = 261617183 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 843772 + ... + 844081.

It is an arithmetic number, because the mean of its divisors is an integer number (40508496).

Almost surely, 2^261617215 is an apocalyptic number.

261617215 is a deficient number, since it is larger than the sum of its proper divisors (62450753).

261617215 is a wasteful number, since it uses less digits than its factorization.

261617215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1687889.

The product of its digits is 5040, while the sum is 31.

The square root of 261617215 is about 16174.5854660946. The cubic root of 261617215 is about 639.5710137882.

The spelling of 261617215 in words is "two hundred sixty-one million, six hundred seventeen thousand, two hundred fifteen".